Components which have high-precision micropatterns are produced by etching. This involves providing them with etch masks using a photolithographic technique. If the micropatterns are complex, i.e., if they have different depths, and are additionally interleaved, two or more etching operations have to be performed.
Since the results of the different etching operations must be precisely positioned relative to each other, it is necessary to accurately align the different etch masks with one another, for which suitable apparatus is available. It is also necessary to be able to check the result of the multistep etching process for accuracy after completion of the micropattern.